Fig. 6

MDSC-Exo promoted PC3 cell proliferation, invasion, and migration by modulating S100A9/circMID1/miR-506-3p/MID1 signaling. A, B PC3 cells were transfected with si-circMID1, miR-506-3p, si-MID1, si-circMID1 and anti-miR-506-3p, or over-MID1, miR-506-3p and over-MID1, and then treated with MDSC-Exo. Cell proliferation (A) was measured by the CCK-8 assay in the PC3 cells with different treatments. Cell migration and invasion (B) was evaluated by Transwell assays of the PC3 cells with the indicated treatments. Scale bar, 100 μM. C Relative expressions of miR-506-3p and MID1 in PC3 cells treated with MDSC-Exo or MDSC-Exo^si−S100A9. ^**P < 0.01, ^* vs. Exo. D Relative expressions of circMID1, miR-506-3p and MID1 in PC3 cells transfected with over-MID1. ^**P < 0.01, ^* vs. control. E, F PC3 cells were transfected with over-circMID1, anti-miR-506-3p and over-MID1, and then treated with MDSC-Exo^si−S100A9. Cell proliferation (E) was measured by the CCK-8 assay, and cell migration and invasion (F) were evaluated by Transwell assays of these PC3 cells with the indicated treatments. ^**,##P < 0.01, ^* vs. Exo, ^# vs. Exo^si−S100A9. All experiments were conducted at least three times